Which of the Following Is True? I

Multiple Choice

Which of the following is true? I.As the real interest rate increases, people increase the quantity they save.
II.The supply of loanable funds curve is downward sloping.
III.As disposable income increases, the supply of loanable funds curve becomes steeper.

A) II and III only
B) I only
C) III only
D) I and III only
E) I, II, and III